Technical Abstract:
The fastidious prokaryote Candidatus Liberibacter solanacearum (Lso), transmitted by the tomato potato psyllid (Bactericera cockerelli), is associated with the Zebra Chip disease of potato. Plants infected with Liberibacter may experience significant yield losses and these plants also serve as potential reservoirs for Liberibacter to spread to other psyllid hosts with alternate crop feeding preferences, potentially introducing new epidemiological focal points among crops. New associations between Liberibacter species and crop plants have been detected in different parts of the world, presenting concerns about the potential roles of these strains in causing disease. Carrots (Daucus carota) showing damage from feeding of carrot psyllids (Trioza apicalis) were recently reported to be infected with Lso. We sequenced and analyzed genomic contigs of psyllids from Finland, Norway and Sweden that showed the presence or absence of Lso. Using Illumina high-throughput short-sequence methods, we generated sequence libraries for all six psyllid samples. To assess the diversity of microbial sequences commonly associated within psyllid microflora as well as to determine the extent of identity to Lso, we removed sequences from the dataset that were closely related to five other microbial reference genomes. Contigs with identity to the different bacterial genomes from all three countries were assembled and differences between the putative Lso strain sequences were identified and contrasted with Lso genome contigs generated from the Texas potato psyllid. Differences between epidemiologically distinct strains may enable identification of infection sources and elucidate variation among regional populations.